Electric lighting fixture



A ril 28, 1942. A. J. o. OHM

ELECTRIC LIGHTING FIXTURE Filed Feb. 21, 1941 INVENTOR azeff fl Okra mmm\\v$ ATTORNEY Patented Apr. 28, 1942 TNT OFFICE 2,281,37 6 ELECTRIC LIGHTING FIXTURE Albert J. D. Ohm, Buffalo, N. Y., assignor to Markel Electric Products, Inc., Bulialo, N. Y., a corporation of New York Application February 21, 1941, Serial No. 379,958

(01. Mil-'78) 4 Claims.

This invention relates to improvements in electric lighting fixtures and, although not necessarily so limited, has characteristics which render it of particular utility in connection with a fluorescent tube fixture of the kind wherein an elongated. difiuser is utilized to modify the light emitted by the tube or tubes of the light source.

One object of the invention is to provide a fixture which is so designed as to avoid the necessity of separate molds for each different length of diffuser which may be required to accommodate different lengths of tubes, this object contemplating a multi-section difiuser built up from sections which are standard withvarious lengths of diffusers and which may be assembled in such numbers as to obtain any desired length of diiiuser.

A further object is to provide for facility in assembling the fixture and in inspecting, removing and replacing the tubes which provide the light source.

A still further object is a fixture in which provision is made for preventing overheating of the parts by the tubes of the light source.

A still further object is to provide a fixture which is simple and inexpensive in design and pleasing and attractive in appearance.

The invention is illustrated in the accompanying drawing in which:

Figure 1 is a side elevation of a fixture embodying the features of the invention.

Figure 2 is a horizontal section taken along line 22 of Figure 1.

Figure 3 is an enlarged vertical section taken along line 33 of Figure 2.

Figure 4 is a fragmentary section taken along line 44 of Figure 3.

Figure 5 is a view similar to Figure 4 illustrating the manner in which a shorter difiuser may be provided by eliminating the central section.

Figure 6 is an enlarged detail section taken along line 6-6 of Figure 2.

The fixture, as illustrated, is of the fluorescent tube type and may be suspended from the ceiling by a hanger assembly Ii], rods ll thereof being suitably connected to the flat top Wall I 2 of a semi-cylindrical shell I3. The tubes [4 (Figure 3) which provide the light source are mounted in parallel relation upon the curved lower wall of the shell and are employed in connection with an elongated diffuser 16, the longitudinal edges of the lower wall of the shell being turned over the corresponding edges of the top wall to provide spaced parallel seats I! fo h d user.

The diffuser It may be of glass or any other suitable material; and it may be either transparent or translucent or have certain Zones which are transparent and others which are translucent. For example, a rectangularly-shaped, beaded top zone lfia may be transparent, as may a horizontal ribbed bottom zone 16b, while the side and end walls Ste may be, and preferably are, translucent. In accordance with the invention the diffuser comprises an assembly of pre-formed, separable sections which are arranged end-toend and, in the embodiment illustrated, includes end sections it and I9 and a central section 20. The outer ends of theend sections are closed and their inner ends are open while both ends of the central section are open. All of the said sections are closed at their bottoms and have side Walls which terminate at their tops in inwardly extending side flanges 2!. The latter rest upon the seats I? to suspend the sections from the shell and in the case of the end sections join, or form continuations of, end flanges 22.

Thedifiuser sections are supported upon the shell l3 so that the open end of the section l8 abuts one of the open ends of the section 20 while the open end of the section l9 abuts the other open end of the section 20, thereby to provide a continuous, elongated envelope which encloses the shell 53 and the tubes M, the side and end flanges of the said sections overlying the top wall of the shell and defining a substantially rectangular opening. In order to prevent the escape of direct light through the joints [6d between the abutting ends of the difiuser sections, the section I3 is preferably formed with a neck portion 23 (Figure 4) which enters the adjacent end of the section 29 while the opposite end of the latter section is formed with a neck portion 24 which enters the open end of the section l9. Preferably the neck portions 23 and 24 of the sections [8 and 20, respectively, are corrugated or otherwise deformed, as illustrated, whereby to provide passages 24a through which air may circulate to cool the tubes and associated parts. A certain amount of air which enters the diffuser may, of course, escape through the spaces between the end fianges of the end sections and he top wall of the shell, the said fianges being spaced from the top wall by the seats I1. In order to prevent the joints Hid from detracting from the appearance of the diffuser, cooperating ornamental designs 25 are formed upon the marginal edges of the open ends of the end sections and central section, the said designs preferably comprising groups of bead-dike emboss nents and the designs upon the ends of the end sections cooperating with the designs upon the ends of the central section to provide composite ornamental figures having character strokes running parallel with and at opposite sides of the joints. The joints are thus effectively obscured and at the same time the appearance of the fixture is enhanced.

Longitudinally extending angle members 25 which are mounted upon the top wall of the shell I 3 serve as guides and cooperate with the marginal edges of the side flanges of the difiuser sections to limit sidewise movement of the sections upon the seats l1. Lengthwise movement of the diffuser sections upon the seats is prevented by upwardly projecting pins 21, one of which is located adjacent each end and substantially midway between the sides of the top wall of the shell. One of the pins 21 extends into an opening 28 in the end flange of one of the end sections of the difiuser while the other pin extends into a similar opening formed in the end flange of the other end section. Movement of the flanges 2| of the diffuser sections away from the seats I! is limited by horizontal flanges 29 of the angle members 26. The flanges 29 overlie but are spaced from the flanges of the diffuser sections to provide clearances 30 (Figure 3) which the flanges 2| of the end sections may move into to permit the end flanges of the end sections to ride up over the pins 2'! so that the pins may enter the openings 28 as the end sections reach their predetermined positions upon the shell l3. The clearances 30 also permit the outer ends of the end sections of the diffuser to be elevated to withdraw the pins 21 from the openings 28 when it is desired to remove the end sections from the shell.

From the foregoing it will be apparent that the seats I! and the angle members 26 provide par- 4 allel longitudinally extending guides for the side flanges of the diffuser sections, that the flanges of the diifuser sections may be caused to enter the guides from either end of the shell and that the central section is held in place by the two end sections. Facility in assembling the sections of the difiuser and in removing them to enable inspection, removal, and replacement of the tubes is thus insured. The construction described has the further advantage that a fixture having any desired length of diffuser may be assembled (assuming a shell having guides of the proper length has been provided) by adding additional sections similar to the section 20 between the end sections. fixture having a shorter diffuser may be provided, if desired, by eliminating the central section and arranging the end sections so that their open ends interfit in the manner shown in Figure 5, it being noted in this connection that the open end of the section I8 is male while that of the section i9 is female and that one end of the central section 20 is male and the other end female. Diffusers having any desired number of central sections or without any central section may, therefore, be assembled to provide a diffuser of the length required to accommodate any particular length of tubes. The use of separate molds for diflerent lengths of diffusers is thus rendered unnecessary.

It will be understood, of course, that although fluorescent tubes are referred to as providing the light source, this is intended by way of example only and that, if desired, any other typ of lamp,

On the other hand, a

tubular or otherwise, may be employed instead.

I claim as my invention:

1. An electric lighting fixture of the character described including a body, a light source, an elongated diffuser for modifying the light emitted by said light source, said diffuser comprising a plurality of preformed sections arranged end-toend and having end sections which are closed at their outer ends and open at their inner ends, means carried by said body for providing spaced longitudinally extending guides, each of said end sections having a transversely extending flange at its closed end and having spaced longitudinally extending flanges which are movable along said guides and which cooperate with the latter to support said sections in a predetermined assembled relation and means on said body for releasably engaging the transversely extending flanges on said end sections to hold said sections against movement off said guides.

2. An electric lighting fixture of the character described including a body, a light source, an elongated difiuser for modifying the light emitted by said light source, said diffuser comprising a plurality of preformed sections arranged end-to-end and having end sections which are closed at their outer ends and which are open at their inner ends, means carried by said body for providing spaced longitudinally extending guides, each of said end sections having longitudinally extending side flanges and a transversely extending end flange, said side flanges being movable along said guides and cooperating with the latter to support said sections in a predetermined assembled relation and a projection on said body which is engageable with an end flange of one of said end sections to hold said section against movement off said guides, said section being movable upwardly with respect to said guides to release said end flange.

3. An electric lighting fixture of the character described including a body, a light source mounted on said body, a difiuser for modifying the light emitted by said light source, said diffuser comprising a plurality of pre-formed sections having longitudinally-extending side flanges and being arranged horizontally end-toend to provide an elongated assembly, longitudinally-extending guides on said body for said flanges, said guides cooperating with said flanges to support saidsections and to limit their lateral movement while permitting them to be assembled on said body and to be removed, at will, by moving them lengthwise in substantially the same horizontal position and plane in which they are supported, and means for engaging one of said sections in its predetermined position on said body to hold it against accidental or unintentional lengthwise movement off said body, said guides permitting said section to be moved upwardly with respect to said body to release it from said means and thereafter to be moved lengthwise to withdraw said flanges from said guides.

4. An electric lighting fixture of the character describedincluding a body, a light source mounted on said body, a diffuser for modifying the light emitted by said light source, said diffuser comprising a plurality of preformed sections having longitudinally-extending side flanges and being arranged end-to-end to provide an elongated assembly, an end section of said diffuser also having a horizontal, transversely extending flange which is formed with an opening, longitudinally-extending guides on said body for said side flanges, said guides cooperating with said side flanges to support said sections and to limit their lateral movement while permitting them to be assembled on said body and to be removed therefrom, at will, by lengthwise movement in substantially the same horizontal position and plane in which they are supported, and a projection on said body which is adapted to enter said opening when said end section approaches a predetermined position on said body to hold said section against accidental or unintentional movement lengthwise of said body, said guides permitting said end section to be moved upwardly with respect to said body to withdraw said projection from said opening and thereafter to be moved lengthwise to withdraw said side flanges from said guides.

ALBERT J. D. OHM. 

